The hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medullary (SAM) systems are implicated in the human stress syndrome. They have been found to be affected by strong metabolic stressors and infusions of CRH. This study investigates the hypothesis that CRH stimulates both the HPA and the SAM systems. In order to determine if CRH was significantly involved in tonic as well as psychologic stress induced catecholamine levels in man, 24 normal male undergraduate students were infused with either saline solutions or dexamethasone.